- #1

RuroumiKenshin

Of course, the idea of an infinite universe could just be based on the inifite boundary theory proposed by Stephen Hawking.

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- #1

RuroumiKenshin

Of course, the idea of an infinite universe could just be based on the inifite boundary theory proposed by Stephen Hawking.

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Infinity is NOT a number.

It is NOT a number.

Thank you. Please bear this in mind.

- #3

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Infinity is the concept of something that goes on forever.

Something infinite cannot expand (IMO).

We can never conclude that the universe is infinite, beyond question.

No, branes are not "sub-universes". Branes are mathematical additions of dimensions (AFAIK).

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- #5

drag

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paradoxical, all the time? What's so paradoxical

about it ? (I guess this should indeed be in the

philosophy forum.)

What's paradoxical about expanding infinity ?

Live long and prosper.

- #6

RuroumiKenshin

Anyhow, infinity is paradoxical because, as Mentat pointed out, something infinite is unable to expand. It goes on, and on, forever so how can something infinite expand?

- #7

RuroumiKenshin

I'm working on it. Any how, I love doing math, because its just like a logic problem, and I love those too.Originally posted by plus

plus, what you said was not insulting. The truth is never,AFAIK, insulting.

- #8

drag

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Well, if it's only spacial expansion for exampleOriginally posted by MajinVegeta

Anyhow, infinity is paradoxical because, as

Mentat pointed out, something infinite is

unable to expand. It goes on, and on, forever

so how can something infinite expand?

then the distances between all objects will

simply grow.

Do understand me people - I'm not, at the moment,

denying the concept of real infinity as having

its own paradox of some kind, but I have yet

to see any clear fomalization of such a paradox.

Live long and prosper.

- #9

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What/who are you talking about?Originally posted by plus

- #10

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No, no, I was talking about the idea that the spacial dimensions themselves are expanding, not just that things are getting farther apart.Originally posted by drag

Greetings !

Well, if it's only spacial expansion for example

then the distances between all objects will

simply grow.

- #11

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Consider the set of the numbers A = {1, 2, 3, ......}, and now consider the set of A and 1/2, so it is B := {1/2, 1, 2, 3, 4, 5, 6, 7, ..}.

Then there is one number in B which is not in A. This could be said to be an expansion of A.

This I believe is a counterexample to one of Mentat's ascertations:

'Something infinite cannot expand',

although he needs say more precisely what he means by this.

- #12

positron98

- #13

drag

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That IS what I meant. Plus gives an appropriateOriginally posted by Mentat

No, no, I was talking about the idea that

the spacial dimensions themselves are

expanding, not just that things are

getting farther apart.

example here.

For example, suppose that you draw coordinates

and assign a number to every area of specific

size. Then multiply your infinite set of areas

by 2 and you'll see that the amount of areas

is now twice the previous amount - between say

your house and the nearest store.

It may be conceptually difficult, but if you

consider that space is infinite you don't have

to worry about what's outside at all - simply

don't bother yourself with that thought.

(I must note that I find it difficult, at this time,

to think of a more solid formalization of this idea,

so perhaps there is a fundumental mistake of some

kind in this line of reasoning.)

Live long and prosper.

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- #15

drag

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it as an example. The question is - what's the

difference ? Is there any ? And why ?

Live long and prosper.

- #16

RuroumiKenshin

- #17

dav2008

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Take all even numbers...you would agree that there are an infinite amount of them....But you can always add an odd number to that set of inifinite numbers...just like "plus" said...

Its more mathematical in that sense...not physical..

- #18

RuroumiKenshin

- #19

Locutus

I believe that what separates the mathematical universe from the physical universe is practicality. Practicality tells us that in order to exist, the universe must have physical laws. These laws (speed of light, for example) impose finite barriers in an attempt to give order to the universe. Even though these laws do prevent many physical infinities (max speed, min temp, etc), the fact that the universe is in constant motion creates many new infinities.Originally posted by MajinVegeta

A common infinity is the coastline of great britain. It is impossible to obtain an exact answer for this, for to do so one must measure at increments infinitely less than planck length, which would require so much energy as to warp space enough to disrupt their results. Not to mention the uncertainty principle...

This is not to say that Britain does not have a definite coastline at a specific increment of time. It does, yet practicality (that word again) prevents us from saying so, because WE cannot obtain this measurement. The physical universe has a human element to it that the mathematical universe lacks. Einstein said that "Only two things are infinite: the universe and human stupidity, and I'm not sure about the former." So perhaps the universe is finite, and humans are so infinitely stupid that they cannot comprehend this.

Perhaps this thread belongs in the "philosophy" forum, but oh well.

- #20

RuroumiKenshin

Anyway, you bring up an excellent point that has been neglected. Although, it occurs to me that the concept of human stupidity being the obstacle of our understanding of the universe seems be undefined. I came upon this conclusion on the premise that everything is relative. If you were traveling at c, the external world would become blue shifted. But to an external observer, you are the one who is blue shifted. So, you, and the observer are both correct for the whole matter is anisotropic and each of you has the right to your observations. Now, from our perspective, the universe is infinite. Possibly, to an "external" observer, the universe, perhaps, is not infinite. I doubt stupidity has anything to do with the matter.

- #21

dr-dock

infinity is the only other singular point as zero is in respect to positive and negative.make XOY system.it's flat surface/plane with 4 infinity points (2 on each axis).now try to do this:

shift x and y for infinity.you'll get that they both begin with -0 and end with +0 while there is only one infinity in the center.i think that XOY should transform into sphere with radius inf/2 where zero and inf are diametricaly oposite.

- #22

RuroumiKenshin

- #23

drag

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Indeed. But, should there be a fundumentalOriginally posted by MajinVegeta

THIS THREAD IS MAINLY

QUESTIONING THE PHYSICAL PARADOXES OF INFINITY.

NOT MATHEMATICAL PROSPECTS.

difference ? And why ?

(I adressed this above, I believe.)

Live long and prosper.

- #24

Stormy

In my mind at least, infinity is something that, not only goes on forever, but also has gone on for ever, well as far as the Physical definition goes (refering to the universe)

- #25

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Mathematics is used to describe the physical universe. Things which are infinite CAN get larger.

A physical example of something getting larger.

Consider the domain in which you are allowed to move in cylindrical coordinates.

Now suppose that at a time t, you are allowed to move in the range

0< theta < t, where theta is the angle in degrees and that there is no restriction on the vertical range or the horizontal distance.

Then up to t=360, although the domain is infinite, it is still expanding. This is not "just a mathematical infinity" it is a practical one, which I have described the only way possible, using mathematics.

NB I could have easily chosen the function so that it increased for ever, but chose this one as it is easier to see what is happening.

Surely you will see now!!!

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